Have 3 yrs old american short Hair(cat) with many allergies. Have corrected by changaing diet and keeping indoors but still have same problem which presented by excessisive scratching to face and head. One of his allergies is cat dandruff which in essence means he is allegic to himself. Current treatment is steriod shot every 4 to 6 weeks as needed but this is life shorting solution. Considering possibilty of Zyrtex but understand no testing results for animals. Blackee needs help....